1. Field of the Invention
This invention relates to pressure control and fluid venting devices, and particularly to systems for simultaneously controlling the pressure and the respective volumes of several fluids within a pressurized container.
2. Description of the Prior Art
In submersible vehicles, electrical equipment, including a battery, is usually housed in an oil filled container which is exposed to the ambient ocean pressure. The internal container pressure is kept just above the local ambient pressure to prevent the container from collapsing (or bursting) by a pressure compensator which pumps (or withdraws) oil from the container as necessary. Several problems have arisen from the normal functioning of the electrical equipment located within such a container: the battery, in discharging, generates O.sub.2 and H.sub.2 gases which displace the oil. Should such gases be allowed to accumulate, the electrical circuits would no longer be submerged in oil and a spark could easily cause an explosion of the trapped gases. If the vehicle is brought to the surface too quickly, the pressure compensator may not have sufficient time to react to lower the internal pressure by withdrawing oil; such could result in the rupture of the container. If the vehicle submerges too quickly to allow the compensator to pump a sufficient quantity of oil into the container, the container could be crushed by the ocean pressure. Water that leaks into the container could, if allowed to accumulate and reach a high enough level, cause corrosion of the electrical contacts and equipment housed inside the container.
Presently, pressurized containers are equipped with valves which provide pressure relief in the situation where the vehicle rises too quickly and also vents internally generated gases. However, such valves are spring loaded, complex, and require precision machining. In addition, the present systems fail to provide a means for quickly increasing the internal pressure in the event of a rapid descent. Nor do they provide a means for venting any water that leaks into the container.
The present invention is a mechanically simple, yet reliable and effective system for providing a pressure compensated container with pressure relief and fluid venting. It also provides for quick pressure compensation in the event of a rapid increase in the ambient pressure, as well as providing for the venting of any water.